With the development of semiconductor related techniques, the number of leads in a semiconductor chip is continuously increased. To accommodate the increased number of leads, the surface area of a packaged semiconductor device is often several times of the related die area. Thus, heat flux on the surface of a package is generally distributed in a non-uniform manner, and hot spots are easily formed. This makes the thermal stress distribution non-uniform and causes damage to the semiconductor chip. Heat pipe is one of the most powerful way to remove heat from a heat-generating device to a heat dissipation device, and heat is dissipated at the heat dissipation device. One of the most common applications of the heat pipe is the electronic devices, such as a notebook computer.
The currently known modes of heat dissipation include: (1) forced air-cooling heat dissipation, (2) forced liquid-cooling heat dissipation, (3) heat pipe phase change heat dissipation, (4) thermo-electrical cooling heat dissipation, and (5) refrigeration heat dissipation. The refrigeration heat dissipation is further classified as micro channel heat sink, micro heat exchanger, micro miniature refrigerator, micro heat pipe, and micro jet droplet cooling.
Those heat dissipation modes that are of high costs and consequently high performance may not be fit for computers, which are generally low-cost devices operated at high power. Thus, development of heat dissipation devices featuring low cost, high performance, and low wearing is certainly a future trend of heat dissipation industry and heat pipe based heat dissipation device is one of the candidates for such a trend.
FIG. 1 of the attached drawings shows a schematic view the structure of a conventional heat pipe, which is broadly designated with reference numeral 100. The conventional heat pipe 100 is comprised of a sealed/enclosed container 1, a capillary structure 2, and a working fluid 3. The enclosed container 1 is evacuated and then filled with a proper amount of the working fluid 3. The container 1 has an end 1a, serving as an evaporator, which when subject to heating, causes the working fluid 3 to evaporate as a result of absorption of the heat and vapor 31 is generated. The vapor 31 flows from the evaporation end 1a toward a condensation end 1b (serving as a condenser) of the container 1 to release the heat thereof. The movement of the vapor 31 is driven by pressure difference between the two ends of the container 1, while the condensate 32 of the vapor, which is in a liquid form 32, is conducted in a reversed direction through the capillarity of the capillary structure 2 back to the evaporator end 1a. The heat pipe operates to dissipate heat by the phase change of substance (working fluid), which absorbs and releases a great amount of heat. The heat pipe achieves very high efficiency of heat removal due to the heat transfer effected by the phase change of the working fluid and thus super thermal conduction is realized.
Heat pipes that are used for heat dissipation of electronic devices are often of a small contact with the heat generating parts and the tubular configuration of the heat pipes also impose limitation to the shape of the heat pipe in actual practices. For example, bending and/or flattening both may damage and even completely eliminate the feature of heat transfer of the heat pipe. To overcome such a problem, manufacturers of heat dissipation devices employs phase change in flat plate based heat dissipation device with the purposes of reduction of overall thickness and elimination of the restriction of splashing of the traditional tubular heat pipe. Such as flat plate based heat dissipation device is often referred to as “plate heat pipe”. A similar technique has been applied in the field of solar energy and is referred to as loop heat pipe, of which an example is schematically shown in FIG. 2 of the attached drawings, comprising an evaporation end 1a which receives heat to evaporate the working fluid 3 located therein into vapor 31, the vapor 31 being guided through a vapor conduit 11a to a condensation end 1b where heat is released from the vapor 31 and the vapor condenses back to liquid to flow back to the evaporation end 1a through a liquid conduit 11b. 
The electronic industry is one of the most prosperous businesses in the world and a great number of new modes or new devices are being developed and marketed. With the performance of the electronic devices being increasingly improved, power consumption is also increased. This leads to accumulation of heat and eventually limits the improvement of the electronic device. Thus, properly installed heat dissipation device to timely remove the heat is a must for the modern electronic industry. The conventional heat dissipation mechanism that is based on fins and fans is apparently insufficient for the modern electronics and heat pipe based heat dissipation device is instead prevailing nowadays. Further, the working fluid e.g. water may spill or leak from the heat pipe and causes the short circuit.
Some of the commonly seen examples of the electronic devices that require high efficiency heat removal include the so-called 3C products (Computers, Communications, and Consumer Electronic Products) and advanced semiconductor devices, such as high power light-emitting diodes (LEDs), lasers, LED arrays, and backlight modules of for example large-sized television sets. To efficiently transfer heat to a condensation zone in order to effectively dissipate heat from a notebook computer, which has a very limited space available for installation of the heat dissipation device, is a critical factor to ensure high performance.
The heat pipe is considered a widely-used high-heat-transfer heat dissipation element for the notebook computer, for it provides, due to the two phase flow occurring therein, a heat transfer capability that is hundreds of times of metals, such as copper, of substantially the same size and is often considered as superconductor for heat.